With development of wireless communication technology, demands of a user for high quality, a high speed, a new service is higher and higher. A wireless communication operator and a device manufacturer should continuously improve a system to meet the demands of the user. In this case, a large amount of spectrum resources are required to support the new service arising continuously, and to meet requirements of high-speed communications, the spectrum resources may be quantized with a parameter such as time, frequency, band width, allowable maximum emitting power.
Currently, limited spectrum resources have been allocated to fixed operators and services, new available spectrum is very rare or expensive. In this case, a concept of dynamic spectrum usage is proposed, that is, frequency resources which have been allocated to certain services but are not utilized sufficiently are utilized dynamically. For example, it is pointed out in the usage specification for a frequency band of 3.5 GHz currently proposed by the Federal Communication Commission that the frequency band of 3.5 GHz is licensed to a radar system, and civil communication systems can make use of the frequency band of 3.5 GHz on the premise of protecting the radar system, and the civil communication systems may include be classified two kinds of systems with high spectrum priority level and with low spectrum priority level.
Therefore, it is desired to provide a manner in which communication systems having different spectrum priority levels can reasonably utilize the spectrum resources.